End ported pump having an improved porting arrangement



United States Patent This invention relates to rotary pumps and pertains more particularly to a rotary pump of the type employing free-fioating roller elements, such as that disclosed in my co-pending patent application for End Ported Rotor Pump, Ser. No. 197,318, filed May 24, 1962, now Patent No. 3,119,345.

In the above-alluded-to patent application, as well as in other rotor pumps having end ports, it is customary to have these ports symmetrically arranged with respect to each other. While such an arrangement provides a pump that is satisfactory, I have found that the efficiency can be improved by adopting a certain unsymmetrical porting arrangement. Accordingly, the present invention has for an object the provision of a rotor type pump having a high pumping efficiency due to a revamped or modified end porting system. The invention has for an additional object the provision of such a pump that can be manufactured without additional cost.

These and other objects and advantages of my invention will more fully appear from the following description, made in connection with the accompanying drawing, wherein like reference characters refer to the same or similar parts throughout the several views and in which:

FIGURE 1 is an end elevational view of a pump construction exemplifying the invention, the view showing the inlet and outlet at one end of the pump;

FIGURE 2 is a vertical section of the pump taken in the direction of line 2--2 of FIGURE 1;

FIGURE 3 is a'view corresponding to FIGURE 1 but with the detachable end wall or face plate removed, the view being taken in the direction of line 3--3 of FIGURE 2;

FIGURE 4 is a view of the inside face of the detachable end wall, the view being taken in the direction of line 4-4 of FIGURE 2, and

FIGURE 5 is a horizontal sectional view taken in the direction of line 55 of FIGURE 1.

Referring now in detail to the drawing, the rotary pump there shown comprises a housing and a rotor assemblage 12 journaled therein. The housing 10 includes a cup-shaped body 14 having an integral plate or end wall 16 and an intermediate circumferential wall 18. Additionally, the housing 10 includes a removable or detachable face plate or end wall 20. The end Wall 20 is provided with four quadrantly spaced holes 21 (FIGURE 4). The upper two holes accommodate .a pair of tap screws 22 that extend into two tapped upper holes 24 (FIGURE 3) located in the cup-shaped body 14. In a somewhat similar fashion, a pair of threaded studs 26 are anchored in a pair of tapped lower holes 2-8 in the cup-shaped body 14. Threaded onto the studs 26 are a pair of set nuts 30 which cooperate in holding the face plate or end wall 20 against the cup-shaped body 14. The studs 26 also function as mounting means for attaching the entire pump to a mounting fixture (not shown), a pair of retaining nuts 32 acting in this capacity.

The integral end wall 16 and the intermediate circumferential wall 18 of the cup-shaped body 14 in combination with the removable end wall 20 form a cylindrical pumping chamber 34. The rotor assemblage 12 is, of course, journaled for rotation within the pumping chamher 34 and the pumping action that takes place will be better understood as the description progresses.

At this time, attention is called to a pair of oppositely directed bosses '36. Contained within each of the bosses 36 is a bearing 38 aligned with shaft openings 40 in the end walls 16 and 20.

Describing now in detail the rotor assemblage 12, it will be discerned that this assemblage includes a rotor body 42 formed with a plurality of angularly disposed roller-receiving slots 44, these slots extending endwise through the circumference of the rotor body and also extending radially inward to the extent shown in FIG- URE 3. It will be noted from the alluded-to figure that the slots are formed with parallel faces, the parallel faces of each slot 44 permitting the inward and outward movement of a cylindrical roller element 46. The rotor body 42 is secured to a shaft 48 by mean-s of a set screw 50.

It is important to observe that the axis of the rotor body 42 is offset from the axis of the pumping chamber 3 4. This is readily accomplished by offsetting the bearings 38 and the shaft openings 40. More specifically, it will be perceived that the eccentric or offsetting of the rotor body 42 is in a vertical plane denoted by the reference numeral 52. This has the result of producing a point of minimum clearance at 54 (FIGURE 3) between the circumferential wall 18 and the circumferential surface of the rotor body 42. By the same token, the offset arrangement in the plane indicated by the reference numeral 52 produces a point 56 (also shown in FIGURE 3) of maximum clearance between the circumferential wall 18 and the circumferential surface of the rotor body 42. As will present-1y be made manifest, the vertical plane 52 serves as a convenient reference with respect to the porting arrangement described below, as do the points 54, 56.

The removable end wall 20 is formed with an inlet port comprised of arcuate openings 58 and 60 separated by a rib or strip 62. Leading directly into the openings 58, 60 of the inlet port is an inlet 64 defined by an internally threaded boss 66. Also contained in the removable end wall 20 is an outlet port comprised of arcuate openings 68 and 70 which are separated by a rib or strip 72. The openings 68, 7t) constituting the outlet port are in direct communication with an outlet 74 formed by an internally threaded boss '76. With the unsymmetrical arrangement of the inlet and outlet ports, the rotor assemblage 12 is shown as rotating in a given direction. This direction has been indicated by an arrow 78 in FIGURES 3 and 4.

While the unsymmetrical arrangement of the inlet and outlet ports is clearly visible in FIGURE 4, it should be understood that this inlet and outlet port pattern also appears in phantom outline in FIGURE 3. Hence, the. pictorial information presented by both FIGURES 3 and 4 will be of considerable help in appreciating the benefits to be derived from a practicing of the instant invention. It will also be of help to assign additional reference characters to portions of the openings constituting the inlet and outlet ports. With this in mind, it is to be perceived that the opening 58 has one end labeled 58a and that this is nearer the plane 52 than is the nearer end 68a of the opening 68. More specifically, it should be understood that the ends 58a, 68a are spaced at angular distance apart somewhat less than the angular distance between the centers of adjacent slots 44. Still further, attention is directed to the fact that the end 58a is closer to the plane 52 by approximately the radius of one of the cylindrical rollers 46, and the end 68a is spaced farther from the plane 52 by approximately the radius of one of the rollers 46. Via such an arrangement, the maximum volume is utilized between the rotor body 42 and the circumferential wall 18 in the region of the previously-mentioned point 56. Stated somewhat differently, one roller 46 will have its end starting to block or close the outer inlet opening 58 whereas the roller immediately preceding the roller juxtaposed with respect to the opening 58 will not as yet have uncovered the outer opening 68. Nonetheless, the maximum amount of space will exist between the circumferential wall 18 and the circumferential surface of the rotor body 42 under these circumstances.

The other ends of the arcuate openings 58, 68 have been denoted by the reference characters 5% and 68b, respectively. Unlike the ends 58a, 68a described above, these ends are equidistant from the plane 52. As for the inwardly spaced openings 60 and 70, it will be noted that the ends thereof bearing the designations 60a and 70a are also substantially equidistant from the plane 52, and by the same token the ends 6% and 70b are the same distance from the plane 52. In the preferred arrangement, the ends 58b, 60b reside in the same plane as the ends 68a, 70a, this plane having been identified by the reference numeral 8%.

Having presented the foregoing information, the manner in which a pump constructed in accordance with the teachings of the present invention operates should be readily understood. As the rotor body 42 rotates in a clockwise direction as viewed in FIGURE 3 (and a counterclockwise direction as viewed in FIGURE 4), this direction having been indicated by the arrow 78, the various rollers 46 will be thrown or flung outwardly by centrifugal force so as to bear against the circumferential wall 18. The clearance between each roller 44 and the side faces of the slot in which it is positioned is quite small so as to prevent passage of fluid from beneath the roller. Inasmuch as each roller maintains contact with the circumferential wall 18 during the pumping operation, it follows that when a given roller 44 passes the approach ends 5811 and 66b of the arcuate openings 58, 60 constituting the inlet port, then continued movement creates zones of reduced pressure. One of these zones exists between the circumferential surface of the rotor body 42 and the circumferential wall 13, this zone increasing in volume as the particular roller moves more and more clockwise after passing the ends 58b and 6%. The other region exists between the roller and the bottom of the slot 44 in which it is constrained to move. Thus, fluid is drawn in through both of the openings 58 and 60 as the rotor 42 rotatively advances. Consequently, fluid remains entrapped between two adjacent rollers as they move in an angular or curvilinear path.

The trailing ends 58a and tla of the openings 58 and 69 are so disposed, the relationship with respect to the plane 52 having already been explained, so that one roller 46 closes the arcuate opening 58 slightly before the preceding roller starts to open the approach end 68a of the arcuate opening 68. At the same time that a given roller is closing the arcuate opening 58, the rotor body 42 starts to block the opening 60, thereby preventing any return of fluid through either of the openings 58, 60 constituting the inlet port.

On the other hand, the roller preceding the one that is shutting off escape of liquid backwardly through the inlet port composed of the openings '58, 6% is beginning to uncover the arcuate opening 68. Likewise, the end of the rotor body 42 begins to uncover the opening 70. This action provides a discharge route that permits fluid to be forced outwardly through the outlet port and thence out through the outlet 74.

Consequently, from the information herein given, it should be understood that the only modification necessary to an existing pump of the envisaged character is the reorienting or revamping of the ports in the removable end plate 20. No other changes are needed in order to improve the efficiency in the manner herein outlined.

It will, of course, be understood that various changes may be made in the form, details, arrangements and proportions of the parts without departing from the scope of my invention as set forth in the appended claims.

What is claimed:

1. An end ported rotary pump comprising:

(a) a housing having longitudinally spaced end walls and an intermediate circumferential wall forming a generally cylindrical pumping chamber;

(b) a rotor rotatably mounted within said pumping chamber with its axis offset from that of the pumping chamber,

(c) said rotor having a plurality of roller-receiving slots formed into and across the circumferential surface thereof and uniformly angularly spaced therearound;

(d) a cylindrical roller disposed for rotation in each of said slots having a length corresponding to the length of said slots,

(e) one of said walls having an arcuate inlet port and an arcuate outlet port,

(f) one end of said inlet port being closer to a plane passing through the axes of said pumping chamber and rotor than the nearer end of said outlet port is to said plane, the angular spacing of said inlet port end from said plane being equal to an angle slightly less than half of the angular distance between adjacent rollers minus a distance equal to the radius of a roller, the angular spacing of said outlet port end being equal to said angle plus a distance equal to a roller radius.

2. An end ported rotary pump comprising:

(a) a housing including a first end wall, an intermediate circumferential wall and a second removable end wall,

(b) said walls forming a generally cylindrical pumping chamber,

(c) a rotor rotatably mounted within said pumping chamber with its axis offset from the axis of said pumping chamber so that the circumferential surface of said rotor is in a proximal relationship with said cirmuf-erential wall at one side and is in a spaced relationship at its other whereby points on said circumferential wall having a spacing with respect to said rot-or lie in a plane including the axes of said pumping chamber and rotor,

(d) said rotor having a plurality of roller-receiving slots formed into and across the circumferential surface thereof,

(e) a cylindrical roller disposed for rotation in each of said slots having a length corresponding to the length of said slots,

(f) said removable end wall having an inlet port constituting two openings at different radii with respect to each other separated by an arcuate strip therebetween and an outlet port also constituting two openings at different radii with respect to each other,

(g) the trailing end of the opening of said inlet port which lies nearest said plane being closer to said plane than the approach end of the opening of said outlet port which lies nearest said plane and the corresponding ends of said inner openings of said inlet and outlet ports being substantially the same distance from said plane.

3. A rotary pump in accordance with claim 2 in which:

(a) the nearer end of the outer opening of said outlet port and the corresponding end of the inner open ing of said outlet port lie in substantially the same plane as the other ends of the inner and outer openings of said inlet port.

4. A rotary pump in accordance with claim 2 in which:

(a) said one end of the outer opening of said inlet port and the nearer end of the outer opening of said outlet port are spaced apart a distance slightly less than the distance between the centers of two rollers, the angular spacing of said one end of the outer opening of said inlet port from said plane being equal to an angle slightly less than half the distance.

3,266,431 5 6 between two rollers minus a distance equal to a 3,072,067 1/1963 Beller 103136 radius of a roller.

MARK NEWMAN, Primuly Examiner.

References Cited bYtheExamin LAURENCE v. EFNER, DONLEY I. STOCKING, UNITED STATES PATENTS Examiners.

2,499,763 3/1950 Livermore 103-136 I. C. MUNRO, R. M. VARGO, Assistant Examiners. 

1. AN END PORTED ROTARY PUMP COMPRISING: (A) A HOUSING HAVING LONGITUDINALLY SPACED ENDS WALLS AND AN INTERMEDIATE CICUMFERENTIAL WALL FORMING A GENERALLY CYLINDRICAL PUMPING CHAMBER; (B) A ROTOR ROTATABLY MOUNTED WITHIN SAID PUMPING CHAMBER WITH ITS AXIS OFFSET FROM THAT OF THE PUMPING CHAMBER, (C) SAID ROTOR HAVING A PLURALITY OF ROLLER-RECEIVING SLOTS FORMED INTO AND ACROSS THE CIRCUMFERENTIAL SURFACE THEREOF AND UNIFORMLY ANGULARLY SPACED THEREAROUND; (D) A CYLINDRICAL ROLLER DISPOSED FOR ROTATION IN EACH OF SAID SLOTS HAVING A LENGTH CORRESPONDING TO THE LENGTH OF SAID SLOTS, (E) ONE OF SAID WALLS HAVING AN ARCUATE INLET PORT AND AN ARCUATE OUTLET PORT, (F) ONE END OF SAID INLET PORT BEING CLOSER TO A PLANE PASSING THROUGH THE AXES OF SAID PUMPING CHAMBER AND ROTOR THAN THE NEARER END OF SAID OUTLET PORT IS TO SAID PLANE, THE ANGULAR SPACING OF SAID INLET PORT END FROM SAID PLANE BEING EQUAL TO AN ANGLE SLIGHTLY LESS THAN HALF OF THE ANGULAR DISTANCE BETWEEN ADJACENT ROLLERS MINUS A DISTANCE EQUAL TO THE RADIUS OF A ROLLER, THE ANGULAR SPACING OF SAID OUTLET PORT END BEING EQUAL TO SAID ANGLE PLUS A DISTANCE EQUAL TO A ROLLER RADIUS. 